https://www.spoj.com/problems/MAIN12B/

#include<bits/stdc++.h>
using namespace std;
#define FAST             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define endl             '\n'
#define loop(i,n)        for(int i=0;i<n;i++)
#define CASE_PRINT       cout<<"Case "<<C<<": "
#define CASE_PRINT2      cout<<"Case "<<C<<":"<<endl
#define ll               long long
#define ld               long double
#define Pi               2*acos(0.0) // acos(-1.0)
#define err              1e-9
int dx[] = {0, 0, +1, -1, +1, +1, -1, -1};
int dy[] = {+1, -1, 0, 0, +1, -1, +1, -1};

const int mx = 1e7+123;
bitset<mx> isPrime; ///if boolean array use n memory, bitset will use (n/32) memory. initially all index 0
vector<int> prime; ///store all prime.

///sieve Function..
void sieve ( int n )
{
    n += 100;///for safety.

    isPrime[2] = 1;
    prime.push_back(2);
    ///all even no composite except 2. loop through only odd no.
    for ( int i = 3; i <= n; i += 2 ) isPrime[i] = 1;///initially all odd are prime.

    int lim = sqrt(n*1) + 2;///for divisor

    for ( int i = 3; i <= n; i += 2 ) {
        if ( isPrime[i] == 1 ) {

           prime.push_back(i);///if we get (i) it must be prime.

           if(i<=lim)///if we don't do it, (i*i) may overflow.
           {
               for ( int j = i*i; j <= n; j += ( i + i ) )isPrime[j] = 0;///cutting all divisor of the prime(i).
           }
        }
    }
}

///Prime Factorization Function..
vector<ll> factor (ll n)
{
    vector<ll> ret;

    for ( auto p : prime ) {
        if ( 1LL * p * p > n ) break;

        if ( n % p == 0 ) {
            ret.push_back (p); ///store just one divisor from same type multiple divisors. remove duplicate

            while ( n % p == 0 ) {
                ///ret.push_back (p);
                n /= p;
            }
        }
    }

    if ( n > 1 ) ret.push_back(n);

    return ret;
}

int main()
{
    FAST;
    sieve(1e6); ///it'll work for (1e14).

    int t,cs = 1;cin>>t;
    while(t--)
    {
        ll n;
        cin >> n ;


        set < ll > ans;

        for(int i=1; i<=n; i++)
        {
            ll num;
            cin>>num;

            vector<ll>v = factor(num);

            for(auto x : v)ans.insert(x);
        }

        cout<<"Case #"<<cs<<": "<<ans.size()<<endl;
        for(auto i : ans)cout<<i<<endl;


        ans.clear();///must use this function for clear factor vector.

        cs++;
    }
}